Radiological Evaluation of a Preoperative First Metatarsal Realignment Test for Metatarsus Primus Varus and Hallux Valgus Correction by the Syndesmosis Procedure

• Published in: Foot & ankle international 2020-03, Vol.41 (3), p.342-349
• Main Authors: Wu, Daniel Yiang, Lam, Eddy Kwok Fai
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Athletic Tape; Female; Hallux Valgus - diagnostic imaging; Hallux Valgus - physiopathology; Hallux Valgus - therapy; Humans; Male; Metatarsal Bones - diagnostic imaging; Metatarsal Bones - physiopathology; Middle Aged; Preoperative Care; Prospective Studies; Radiography; Range of Motion, Articular; Young Adult
• ISSN: 1071-1007; 1944-7876
• DOI: 10.1177/1071100719893339

Background: Metatarsus primus varus correction is one of the primary surgical objectives for hallux valgus correction. Some soft tissue procedures have shown that the first metatarsal can be adequately realigned without osteotomy. The hypothesis of this study was that this correctability should also be demonstrable preoperatively. The purpose of this study was to assess whether a simple forefoot taping technique could do so and whether it could also be correlated with operative results after the syndesmosis procedure. Methods: Between May 2014 and December 2015, 147 feet with hallux valgus from 85 patients with an average age of 46.2 years underwent the syndesmosis procedure. All were followed prospectively with standing radiographic assessment of their first intermetatarsal angle, metatarsophalangeal angle, and medial sesamoid position preoperatively without and with a forefoot wrapping technique and postoperatively at 10 days, 6 months, and 1 year. Results: Their average preoperative intermetatarsal angle was reduced from 14.4 to 8.4 degrees by the wrapping technique, and their average metatarsophalangeal angle was spontaneously reduced from 31.8 to 21.8 degrees. After a minimum 1-year follow-up, they stabilized at 7.4 and 18.6 degrees, respectively. There was significant correlation between hallux valgus and metatarsus primus varus corrections by both forefoot wrapping and surgical methods with Spearman’s rank correlation of metatarsophalangeal angle and intermetatarsal angle corrections (r = 0.6077, P < .0001 due to the wrapping method; r = 0.7157, P < .0001 due to the syndesmosis procedure). All raw working radiographic images for this study can be viewed in the Supplemental Material section. Conclusion: This study found that a simple forefoot tape-wrapping technique could be used preoperatively to verify first metatarsal mobility for metatarsus primus varus correction by the soft tissue syndesmosis procedure without osteotomies. Level of Evidence: Level II, prospective comparative study.